The present invention relates to a coffee machine and more particularly to a coffee machine comprising an integrated device enabling steam to be delivered in order to heat and emulsify a liquid. The coffee machine forming the subject of the invention is thus particularly well suited for the making of cappuccino, which is obtained by adding hot, foaming milk to the coffee.
Some coffee machines of the traditional xe2x80x9cespressoxe2x80x9d type possess, in addition to the components necessary for the preparation of coffee, a steam jet emerging from the housing of the machine. A switch generally enables the operating mode of the machine to be selected. In a first operating mode, the water contained in the tank is aspirated by a pump which directs it to a heater unit enabling it to be heated. The hot water is then delivered to a percolation nozzle on which is fitted a filter-holding or cartridge-holding device containing the ground coffee. In a second mode of operation, the hot water is passed to the steam jet in order to produce either hot water or steam.
In order to heat and emulsify a liquid such as milk, it is necessary to plunge the steam jet into a receptacle containing the liquid to be heated.
These machines have disadvantages regarding maintenance and ease of use. In order to heat or emulsify a liquid, it is necessary to bring the receptacle containing the liquid below the jet and to hold it in a position such that the distal end of the jet is immersed in the liquid. The steam gushing from the jet causes splashing if it is not completely immersed in the receptacle or if the latter does not contain sufficient liquid.
Another disadvantage arises from the fact that the steam jet is solidly fixed to the frame of the coffee machine. It cannot therefore be dismantled for cleaning purposes, which may incidentally result in hygiene problems. Accordingly, there is a need for improvements in these type machines.
The present invention remedies the abovementioned disadvantages by providing a coffee machine of the xe2x80x9cespressoxe2x80x9d type possessing an integrated device making it possible to emulsify a liquid, such as milk for example. This device is extremely simple to use and easy to maintain, and makes it possible to prevent any undesirable splashing of liquid.
The invention specifically relates to a coffee machine comprising a water tank, a pump, a heater unit, passages for feeding hot water and steam to a percolation nozzle, a receptacle containing a liquid to be heated or emulsified, a closure covering the receptacle and including an aperture, and an integrated steam delivery device. The steam device comprises a steam inlet connected to a steam feeding passage, a steam outlet, and means for moving the steam outlet into contact with the closure aperture.
The enabling means preferably comprises a hollow body having a radial aperture, a movable piece, a resilient member for moving the movable piece within the body, and a control member operatively associated with the resilient member for moving the steam outlet when desired. The control member preferably includes a control finger emerging from the frame of the machine and pivotable about a pivot, one end of which is solidly fixed to the body and the other end of which is shaped like a sprout. If desired, guide means for the receptacle may be included. Thus, the control finger can act on a microswitch for controlling the production of steam, and be displaced by a lateral wall of the receptacle when the latter is in the operating position defined by the guide means.
The closure of the receptacle can include a steam tube connected to the aperture in the closure and directed towards the receptacle interior. If desired, the closure of the receptacle can include aspiration means for allowing the liquid to be aspirated by the tube and directed towards an outlet jet by a venturi effect. In this embodiment, the aspiration means are formed by an intake chamber communicating in its upper part with a pipe connected to the steam tube and in its lower part with a pipe ending in an aperture of the outlet jet. Also, the outlet jet may be pivotably mounted in the closure and, depending on its relative position with relation to the closure, it allows liquid to pass towards the outlet or steam to enter directly into the receptacle.
In a preferred embodiment, the closure of the receptacle comprises a steam tube, an outlet jet and an internal jet, with the outlet tube being pivotable to different positions to enable the liquid to emerge either to the outlet jet or to the internal jet. Also, a base can be included, preferably one that is provided with guide means and stop means that define a seating intended to accommodate and maintain the receptacle in an operating position.
Another embodiment of the invention relates to a receptacle for emulsifying a liquid, comprising a leaktight closure having an aperture connected to a steam tube that extends into the receptacle, the aperture of the receptacle being intended to be connected to the steam outlet of a coffee machine, such as one of those described herein. As above, the aperture can be connected to an intake chamber which is itself connected on one side to an outlet jet and on the other side by a venturi tube to the steam tube. Also, the outlet jet is preferably pivotable in the closure of the receptacle and, depending on its relative position in relation to the closure, a connection to the intake chamber is sealed or opened. Advantageously, the aperture is shaped so as to be automatically connected to the steam outlet of a coffee machine when the receptacle is positioned on that machine, and can be connected to an intake chamber, which is itself connected to an outlet jet, by a venturi tube to a steam tube and to an internal jet.